uvm_fault(0xfffffd806f3b85c0, 0x98, 0, 1) -> e fatal page fault in supervisor mode trap type 6 code 0 rip ffffffff81f340d8 cs 8 rflags 10246 cr2 98 cpl 0 rsp ffff8000363cee30 gsbase 0xffff8000299bdff0 kgsbase 0x0 panic: trap type 6, code=0, pc=ffffffff81f340d8 Starting stack trace... panic(ffffffff83485042) at panic+0x1d0 sys/kern/subr_prf.c:229 kerntrap(ffff8000363ced80) at kerntrap+0x30b alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b dovutimens(ffff800039fc34e8,fffffd806440cb38,ffff8000363cef60) at dovutimens+0x368 sys/kern/vfs_syscalls.c:2771 sys_futimes(ffff800039fc34e8,ffff8000363cf0b0,ffff8000363cf000) at sys_futimes+0x208 sys/kern/vfs_syscalls.c:2813 syscall(ffff8000363cf0b0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000363cf0b0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x5eb65d9a9c0, count: 250 End of stack trace. WARNING: SPL NOT LOWERED ON SYSCALL 87 3 EXIT 0 4 Stopped at savectx+0xae: movl $0,%gs:0x688 TID PID UID PRFLAGS PFLAGS CPU COMMAND *323922 9088 0 0 0 1 syz-executor 41102 3284 0 0 0 0 syz-executor savectx() at savectx+0xae end of kernel end trace frame: 0x7412e5e385b0, count: 14 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs. ddb{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: uvm_fault(0xfffffd806f3b85c0, 0x98, 0, 1) -> e ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x7412e5e385b0, count: -1 ddb{1}> show registers rdi 0 rsi 0 rbp 0xffff8000363b7670 rbx 0 rdx 0 rcx 0xffff800039fc3cb0 rax 0x32 r8 0xffff8000363b75a0 r9 0x1 r10 0xa13c2e44577dcd51 r11 0x88d7c5e40c7898ba r12 0 r13 0 r14 0xffff800039fc3cb0 r15 0 rip 0xffffffff8260f3ee savectx+0xae cs 0x8 rflags 0x46 rsp 0xffff8000363b75f0 ss 0x10 savectx+0xae: movl $0,%gs:0x688 ddb{1}> show proc PROC (syz-executor) tid=323922 pid=9088 tcnt=2 stat=onproc flags process=0 proc=0 runpri=50, usrpri=86, slppri=17, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff800039fc22c0,0xffff800039fc2038 process=0xffff80003c3f4020 user=0xffff8000363b2000, vmspace=0xfffffd806c7467b8 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 58006 224258 86560 0 2 0 syz-executor 58006 331542 86560 0 3 0x4000000 sbar syz-executor 3574 94060 34303 0 2 0 syz-executor 3574 189231 34303 0 3 0x4000080 fsleep syz-executor * 9088 323922 89963 0 7 0 syz-executor 9088 302991 89963 0 3 0x4000000 biowait syz-executor 77835 303070 85973 0 2 0 syz-executor 77835 75732 85973 0 3 0x4000080 fsleep syz-executor 77835 1270 85973 0 3 0x4000080 fsleep syz-executor 3284 41102 28407 0 7 0 syz-executor 3284 501793 28407 0 3 0x4000080 fsleep syz-executor 99172 332598 98171 0 2 0 syz-executor 99172 29925 98171 0 3 0x4000080 lockf syz-executor 99172 36981 98171 0 3 0x4000080 fsleep syz-executor 56559 158814 88219 0 2 0 syz-executor 56559 235349 88219 0 3 0x4000080 fsleep syz-executor 56559 380453 88219 0 3 0x4000080 fsleep syz-executor 2957 213987 69833 -1 2 0x10 syz-executor 2957 85913 69833 -1 3 0x4000090 piperd syz-executor 2957 475776 69833 -1 3 0x4000090 fsleep syz-executor 98171 123366 66504 0 3 0x82 nanoslp syz-executor 24881 333213 0 0 3 0x14200 acct acct 28407 753 66504 0 3 0x82 nanoslp syz-executor 34303 226607 66504 0 3 0x82 nanoslp syz-executor 85973 249612 66504 0 3 0x82 nanoslp syz-executor 89963 31857 66504 0 3 0x82 nanoslp syz-executor 69833 342705 66504 0 3 0x82 nanoslp syz-executor 88219 254743 66504 0 3 0x82 nanoslp syz-executor 86560 396441 66504 0 3 0x82 nanoslp syz-executor 66504 202298 69424 0 3 0x82 kqread syz-executor 69424 16442 91603 0 3 0x10008a sigsusp ksh 91603 367862 25543 0 3 0x98 kqread sshd-session 25543 283462 83231 0 3 0x92 kqread sshd-session 33263 514021 1 0 3 0x100083 ttyin getty 83231 171018 1 0 3 0x88 kqread sshd 76022 325741 56558 74 3 0x1100092 bpf pflogd 56558 40561 1 0 3 0x80 sbwait pflogd 35620 36518 33911 73 3 0x1100090 kqread syslogd 33911 55762 1 0 3 0x100082 sbwait syslogd 12934 148227 1 0 3 0x100080 kqread resolvd 99648 171269 16080 77 3 0x100092 kqread dhcpleased 50332 129057 16080 77 3 0x100092 kqread dhcpleased 16080 341221 1 0 3 0x80 kqread dhcpleased 67340 196329 0 0 3 0x14200 bored smr 81215 248993 0 0 2 0x14200 zerothread 79405 145577 0 0 3 0x14200 aiodoned aiodoned 11287 205132 0 0 3 0x14200 syncer update 88253 491984 0 0 3 0x14200 cleaner cleaner 68671 133555 0 0 3 0x14200 reaper reaper 79177 59711 0 0 3 0x14200 pgdaemon pagedaemon 60282 445151 0 0 3 0x14200 bored viomb 23221 220540 0 0 3 0x40014200 acpi0 acpi0 66887 111854 0 0 3 0x40014200 idle1 29755 264974 0 0 3 0x14200 bored softnet1 57617 40022 0 0 3 0x14200 netlock softnet0 26059 400898 0 0 2 0x14200 systqmp 89143 378640 0 0 3 0x14200 bored systq 12586 504458 0 0 3 0x14200 tmoslp softclockmp 5107 43944 0 0 3 0x40014200 tmoslp softclock 88669 423334 0 0 3 0x40014200 idle0 1 49212 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 58006 (syz-executor) thread 0xffff800039fc34e8 (331542) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff839be540) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] #1 syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783 #2 Xsyscall+0x128 Process 9088 (syz-executor) thread 0xffff800039fc2fb8 (302991) exclusive rrwlock inode r = 0 (0xfffffd806c6bb310) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576 #5 vget+0x2a2 sys/kern/vfs_subr.c:686 #6 ufs_ihashget+0x185 sys/ufs/ufs/ufs_ihash.c:98 #7 ffs_vget+0x8c sys/ufs/ffs/ffs_vfsops.c:1203 #8 ufs_lookup+0x1a36 sys/ufs/ufs/ufs_lookup.c:478 #9 VOP_LOOKUP+0x6e sys/kern/vfs_vops.c:85 #10 vfs_relookup+0xd4 sys/kern/vfs_lookup.c:788 #11 ufs_rename+0x14aa sys/ufs/ufs/ufs_vnops.c:1007 #12 VOP_RENAME+0x137 sys/kern/vfs_vops.c:376 #13 dorenameat+0x3f7 sys/kern/vfs_syscalls.c:3064 #14 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #14 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #15 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806fa09a08) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 rw_do_enter_write+0x419 sys/kern/kern_rwlock.c:320 #2 rrw_enter+0xc6 sys/kern/kern_rwlock.c:621 #3 VOP_LOCK+0xbd sys/kern/vfs_vops.c:527 #4 vn_lock+0xa4 sys/kern/vfs_vnops.c:576 #5 vfs_relookup+0x5c sys/kern/vfs_lookup.c:779 #6 ufs_rename+0x14aa sys/ufs/ufs/ufs_vnops.c:1007 #7 VOP_RENAME+0x137 sys/kern/vfs_vops.c:376 #8 dorenameat+0x3f7 sys/kern/vfs_syscalls.c:3064 #9 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #9 syscall+0xb17 sys/arch/amd64/amd64/trap.c:783 #10 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11068 12163K 12446K 166960K 13185 0 pcb 19 12K 12K 166960K 87 0 rtable 232 7K 8K 166960K 455 0 pf 34 17K 19K 166960K 59 0 ifaddr 41 7K 7K 166960K 56 0 ifgroup 55 2K 2K 166960K 74 0 sysctl 4 1K 9K 166960K 9 0 counters 70 37K 37K 166960K 84 0 ioctlops 0 0K 4K 166960K 1683 0 iov 0 0K 16K 166960K 32 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1354 85K 86K 166960K 1905 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 3 0 VM map 2 1K 1K 166960K 2 0 sem 22 312K 312K 166960K 34 0 dirhash 12 2K 2K 166960K 18 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 89K 166960K 667 0 sigio 0 0K 0K 166960K 7 0 proc 72 115K 164K 166960K 622 0 subproc 72 4K 4K 166960K 81 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 49 0 in_multi 94 6K 7K 166960K 121 0 ether_multi 1 0K 0K 166960K 3 0 mrt 0 0K 0K 166960K 17 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 67 307K 307K 166960K 67 0 exec 0 0K 1K 166960K 457 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 245 167K 192K 166960K 7731 0 UVM aobj 80 4K 4K 166960K 80 0 pinsyscall 43 86K 104K 166960K 1860 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 7 0 NDP 12 0K 1K 166960K 36 0 temp 46 9076K 9153K 166960K 33917 0 kqueue 15 22K 28K 166960K 115 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 26 0 0 1 0 1 1 0 8 0 rtpcb 120 76 0 73 1 0 1 1 0 8 0 rtentry 176 137 0 34 6 0 6 6 0 8 0 unpcb 144 289 0 272 2 0 2 2 0 8 1 syncache 336 7 0 7 1 0 1 1 0 8 1 tcpcb 736 99 0 95 1 0 1 1 0 8 0 arp 136 25 0 8 1 0 1 1 0 8 0 inpcb 328 554 0 544 12 3 9 12 0 8 7 nd6 152 29 0 5 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 kcovpl 48 9 0 1 1 0 1 1 0 8 0 ppxss 1192 4 0 4 1 0 1 1 0 8 1 pffrag 232 5 0 2 1 0 1 1 0 482 0 pffrnode 88 3 0 0 1 0 1 1 0 8 0 pffrent 40 8 0 5 1 0 1 1 0 8 0 pfosfp 40 1428 0 1005 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfsrclim 320 1 0 1 1 1 0 1 0 8 0 pfstitem 24 53 0 1 1 0 1 1 0 8 0 pfstkey 128 53 0 1 2 0 2 2 0 8 0 pfstate 448 53 0 1 6 0 6 6 0 8 0 pfrule 1360 22 0 17 2 1 1 2 0 8 0 rttmr 136 1 0 1 1 0 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 545 0 102 30 0 30 30 0 8 2 art_table 40 546 0 102 5 0 5 5 0 8 0 art_node 32 137 0 45 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 2 1 0 1 1 0 8 0 semapl 112 29 0 9 1 0 1 1 0 8 0 shmpl 112 77 0 0 3 0 3 3 0 8 0 dirhash 1024 21 0 4 3 0 3 3 0 8 0 dino2pl 256 2583 0 1124 93 0 93 93 0 8 0 ffsino 296 2583 0 1124 114 0 114 114 0 8 1 nchpl 144 3452 0 1746 64 0 64 64 0 8 0 vnodes 216 2962 0 0 165 0 165 165 0 8 0 namei 1024 11106 0 11104 3 1 2 2 0 8 1 percpumem 16 57 0 7 1 0 1 1 0 8 0 kstatmem 264 39 0 12 2 0 2 2 0 8 0 scsiplug 72 4 0 4 1 0 1 1 0 8 1 scxspl 216 15950 0 15949 11 3 8 8 1 8 7 plimitpl 152 175 0 158 1 0 1 1 0 8 0 sigapl 424 984 0 935 7 1 6 7 0 8 0 knotepl 120 532 0 0 17 0 17 17 0 8 0 kqueuepl 224 169 0 159 2 0 2 2 0 8 1 pipepl 344 156 0 128 3 0 3 3 0 8 0 fdescpl 528 967 0 935 3 0 3 3 0 8 0 filepl 160 4759 0 4475 15 0 15 15 0 8 2 lockfpl 104 239 0 234 1 0 1 1 0 8 0 lockfspl 48 84 0 80 1 0 1 1 0 8 0 sessionpl 144 40 0 31 1 0 1 1 0 8 0 pgrppl 48 53 0 36 1 0 1 1 0 8 0 ucredpl 104 736 0 722 1 0 1 1 0 8 0 zombiepl 144 935 0 935 1 0 1 1 0 8 1 processpl 1232 984 0 935 5 0 5 5 0 8 1 procpl 664 1804 0 1743 6 0 6 6 0 8 0 sosppl 176 3 0 3 1 0 1 1 0 8 1 sockpl 752 934 0 904 17 6 11 17 0 8 7 mcl64k 65536 5 0 0 1 0 1 1 0 8 0 mcl16k 16384 7 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 8 0 0 1 0 1 1 0 8 0 mcl4k 4096 116 0 0 15 0 15 15 0 8 0 mcl2k 2048 29 0 0 4 0 4 4 0 8 0 mtagpl 96 5 0 0 1 0 1 1 0 8 0 mbufpl 256 243 0 0 15 0 15 15 0 8 0 bufpl 280 5864 0 108 412 0 412 412 0 8 0 anonpl 32 9773 0 0 80 1 79 80 0 246 0 amapchunkpl 152 25376 0 24862 35 0 35 35 0 158 15 amappl16 200 3488 0 3456 29 14 15 22 0 8 11 amappl15 192 63 0 63 1 1 0 1 0 8 0 amappl14 184 439 0 438 1 0 1 1 0 8 0 amappl13 176 133 0 121 1 0 1 1 0 8 0 amappl12 168 1227 0 1195 2 0 2 2 0 8 0 amappl11 160 6 0 6 1 1 0 1 0 8 0 amappl10 152 68 0 54 1 0 1 1 0 8 0 amappl9 144 262 0 261 2 1 1 1 0 8 0 amappl8 136 109 0 107 1 0 1 1 0 8 0 amappl7 128 159 0 145 1 0 1 1 0 8 0 amappl6 120 184 0 182 1 0 1 1 0 8 0 amappl5 112 105 0 94 1 0 1 1 0 8 0 amappl4 104 315 0 296 1 0 1 1 0 8 0 amappl3 96 4916 0 4794 4 0 4 4 0 8 0 amappl2 88 579 0 516 2 0 2 2 0 8 0 amappl1 80 12877 0 12280 16 0 16 16 0 8 2 amappl 88 6889 0 6718 5 0 5 5 0 92 0 uvmvnodes 80 117 0 0 3 0 3 3 0 8 0 dma32768 32768 1 0 1 1 0 1 1 0 8 1 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 257 0 257 2 1 1 1 0 8 1 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 72 79 0 0 2 0 2 2 0 8 0 uaddrrnd 24 967 0 935 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 967 0 935 1 0 1 1 0 8 0 vmmpekpl 168 9693 0 9657 3 0 3 3 0 8 0 vmmpepl 168 69637 0 67666 103 0 103 103 0 357 14 vmsppl 488 966 0 935 5 0 5 5 0 8 0 rwobjpl 80 21999 0 20861 31 0 31 31 0 8 2 pdppl 4096 1941 0 1870 103 32 71 85 0 8 0 pvpl 32 17200 0 0 140 1 139 140 0 265 0 pmappl 256 966 0 935 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 287 0 36 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff838dfff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff839bdd40) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839bdd40) at __mp_lock+0x199 sys/kern/kern_lock.c:173 intr_handler(ffff8000363b0f10,ffff800000079600) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:560 Xintr_ioapic_edge16_untramp() at Xintr_ioapic_edge16_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c sys/dev/kcov.c:153 __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173 intr_handler(ffff8000363b1080,ffff8000002a3480) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:560 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x38 sys/dev/kcov.c:-1 __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173 syscall(ffff8000363b1260) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff8000363b1260) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x72e60bbd0ff0, count: 1 ddb{0}> trace x86_ipi_db(ffffffff838dfff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff839bdd40) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839bdd40) at __mp_lock+0x199 sys/kern/kern_lock.c:173 intr_handler(ffff8000363b0f10,ffff800000079600) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:560 Xintr_ioapic_edge16_untramp() at Xintr_ioapic_edge16_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c kd_curproc sys/dev/kcov.c:584 [inline] __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x2c sys/dev/kcov.c:153 __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173 intr_handler(ffff8000363b1080,ffff8000002a3480) at intr_handler+0xe9 sys/arch/amd64/amd64/intr.c:560 Xintr_ioapic_edge23_untramp() at Xintr_ioapic_edge23_untramp+0x18f __sanitizer_cov_trace_pc() at __sanitizer_cov_trace_pc+0x38 sys/dev/kcov.c:-1 __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff839bdd40) at __mp_lock+0x1a3 sys/kern/kern_lock.c:173 syscall(ffff8000363b1260) at syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] syscall(ffff8000363b1260) at syscall+0xaf4 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x72e60bbd0ff0, count: -14 ddb{0}> machine ddbcpu 1 Stopped at savectx+0xae: movl $0,%gs:0x688 savectx() at savectx+0xae end of kernel end trace frame: 0x7412e5e385b0, count: 14 ddb{1}> trace savectx() at savectx+0xae end of kernel end trace frame: 0x7412e5e385b0, count: -1